A known type of a fuel cell for generating electricity by utilizing electrochemical reaction between hydrogen and oxygen is a solid oxide fuel cell (hereinafter may be referred to as “SOFC”) which includes electrolyte layers containing a solid oxide. A fuel cell electricity generation unit (hereinafter may be referred to simply as an “electricity generation unit”), which is the smallest unit of electricity generation of an SOFC, includes a unit cell of fuel cell (hereinafter may be referred to simply as a “unit cell”) and a separator. The unit cell includes an electrolyte layer, a cathode, and an anode such that the cathode and the anode face each other in a predetermined direction (hereinafter may be referred to as “direction of array”) and the electrolyte layer intervenes between these electrodes. The separator has a through hole extending in the direction of array, and a portion of the separator surrounding the through hole (hereinafter the portion may be referred to as “through hole surrounding portion”) is bonded to a peripheral portion of the unit cell by means of a bonding member containing a brazing material, whereby an air chamber facing the cathode is separated from a fuel chamber facing the anode.
In the electricity generation unit having the aforementioned configuration, gas leakage (cross leakage) may occur between the air chamber and the fuel chamber through the bonding member that bonds the unit cell to the separator. A known configuration for preventing such cross leakage includes a glass sealing member provided so as to be in contact with both the surface of the separator and the surface of the unit cell, thereby sealing between the air chamber and the fuel chamber (see, for example, Patent Document 1).